Over the past decade, an increasing amount of renewable energy supply has been added to the power grids of major markets, such as the United States and Europe. One of the challenges in the use of renewable energy is that the renewable energy source must be supplemented by using energy storage to prevent supply gaps due to its intermittent and unpredictable nature. Another challenge is the need for electricity to heat and cool homes during the different seasons as well as the operating strategy of various sections of a power grid. The seasonal use of power does not necessarily match up with the availability of power from renewable resources. With all these influencing factors on the electrical power supply, combined cycle power plants must be able to ramp up and down quickly to respond to the demand. Such is especially true where a financial penalty is applicable when a power plant cannot reach a load requested by power grid operators.
Conventional power generation systems have used simple cycle power plants to handle loads requiring fast ramp up and ramp down intervals. While simple cycle power plants are capable of fast changes in output, the simple cycle power plants cost more to operate as their overall efficiency is below that of a combined cycle plant and environmental considerations such as emissions associated with the installation of a simple cycle power plant can undermine their viability. Other conventional combined cycle power generation systems have used duct firing in a heat recovery steam generator to increase the steam generated in the heat recovery steam generator to increase output from steam turbine engines. This system has a slow response time because the system is thermodynamically limited by the time required for the additional steam to be generated and the steam turbine engines to respond with greater output once the additional steam input is received. Currently, the maximum plant ramp up capability is just under five megawatts per minute. However, power grid controllers are more often requesting a ramp up rate far faster than five megawatts per minute. Thus, a need exists for a power plant capable with a faster ramp up rate.